Directed flow of deuterons in Xe+Cs(I) collisions at Ekin=3.8A GeV at the BM@N experiment

At the beam energies of several GeV per projectile, nucleon dense baryonic matter is produced similar to that observed in astrophysical phenomena as neutron star mergers. The initial asymmetry of the energy distribution in the overlap region, governed by the properties of the created matter, evolves into momentum anisotropy of the final-state particles. Thus the coefficients of the Fourier decomposition of the azimuthal distribution of the particles produced in the collision are a sensitive probe of these properties. In 2022–2023 BM@N, the first experiment on the NICA accelerator complex in JINR, Russia, finished its first physical run collecting more than 500M [Formula: see text](I) collisions at [Formula: see text] [Formula: see text]GeV. In this paper, we present the first results on the analysis of the directed flow ([Formula: see text]) of deuterons and compare obtained results with existing world data. Additionally, the scaling of the directed flow with mass number for light nuclei is examined.